Percussion tool holder



June 2 7, 1967 E. ANDERSON 3,327,516

PERCUSSION TOOL HOLDER Filed July 22, 1964 INVENTOR ELMER ANDERSON ATTORNEY United States Patent 3,327,516 PERCUSSION TOOL HOLDER Elmer Anderson, St. Charles, 111., assignor of one-third to Carroll W. Hoshour and one-third to Nicholas M. Esser, both of Roselle, Ill.

Filed July 22, 1964, Ser. No. 384,413 6 Claims. (Cl. 72-462) This invention relates in general to tool holders and more specifically to a holder for a series of tools of the type requiring percussion or one or more blows to accomplish their intended function.

Heretofore tools of this general class have for the most part been one piece. Thus, for a variety of sizes and uses, a multiplicity of complete tools were required. This is due to the fact that chucks, threaded connections or magnetic couplings do not lend themselves to coupling a percussion tool to the tool holder, as the blows necessary to their function would of necessity damage chuck jaws, peen threaded connections, and demagnetize magnetic couplings.

Applicant has discovered a novel and effective means of magnetically coupling percussion tools to a tool holder which permits the user to have available many sizes of several types of percussion tool bits or inserts readily coupled to a single tool holder without fear of demagnetizing the tool holder element as blows are applied to it and transmitted via the tool inserts to the workpiece. The foregoing constitutes the principal object of this invention. Additional advantages and features of the invention will become more apparent as the following description unfolds, taken in conjunction with the accompanying drawing in which:

FIGURE 1 is an elevation, partly in longitudinal section, of the percussion tool holder.

FIGURES 2 and 3 are respective end views of the tool holder illustrated in FIGURE 1.

FIGURES 4 to 9 inclusive illustrate various percussion tool bits or inserts adapted to be inserted into and magnetically coupled to the tool holder.

FIGURE 10 illustrates an intermediate insert adapted to be inserted into and magnetically coupled to the tool holder, which insert is in turn adapted to magnetically couple to steel ball punch elements of a variety of sizes.

Referring again more particularly to FIGURE 1, the numeral 10 generally designates the tool holder or handpiece, preferably cylindrical in shape and having a solid end 11 terminating in a fiat imperforate head 12. This end may be of any material of sufiicient hardness to withstand the impact of blows against its fiat head 12. How ever, as the other end which houses the magnetic coupling device must be of a non-magnetic material, it may be found expedient for the entire tool holder to be of a sufficiently hard non-magnetic material, such as for example stainless steel 18-8 bar stock.

The insert end 13 of the tool holder 10. opposite fiat head 12, is provided with a center bore 14 and, in the embodiment illustrated, an end counter bore 15. Into the center bore 14 are inserted first a cushioning element 16 such as buna rubber or plastic such as nylon or Teflon. Next there is placed in the center bore 14 a permanent magnet 17, preferably cylindrical in shape. This permanent magnet may be any suitable kind such as Alnico. The magnetic element 17 need only be of such an outside dimension to be slidable within the center bore 14. The cushion 16 may also be slidable or press fit into the inner end of the center bore 14. Into the counter bore there is press fit a tubular insert 18, also preferably of non-magnetic material. The tubular insert 18 is a convenient means for maintaining the permanent magnet 17 captive between it and the cushion. This could also be accomplished in other ways without the counter bore and 3,327,515 Patented June 27, 1967 tubular insert 18 by, for example, scoring out a circumferential seat in the center bore 14 at approximately the position where the counter bore 15 as illustrated terminates, into which could be seated a snap ring, thus maintaining the permanent magnet 17 captive between the snap ring and cushion 16. The important aspect is that unoccupied space remains in the center bore 14 after the cushion 16 and magnet 17 have been made captive, as by insert sleeve 18, and within which space the permanent magnet is free to move.

FIGURES 4 through 9 illustrate percussion tools, all of magnetic material such as high carbon steel, in the nature of a nail set, eyelet tool, rivet tool, flat punch, center punch, and gasket hole cutter respectively. Each is provided with a shank 20 to 25 respectively, approximately the same length as the bore of the tubular insert 18, extending from a shoulder 26 to 31 respectively. The shanks are adapted to slidably fit into the bore 19 of the tubular insert 18 where they are held in place by engagement or near engagement with the permanent magnet 17.

FIGURE 10 illustrates a holder adapter having a shank 32 and shoulder 33 much the same as the eyelet tool illustrated in FIGURE 5. However, the face of the shoulder portion 33 is provided with a concave surface 34. The concave surface preferably is a spherical section having a radius adapted to receive a number of ball punch elements such as solid steel ball 35 of various diameters; The preferable radius is that of the smallest ball 35 desired so that larger balls, although not fully seated, may seat on'a circular line. Here again, the ball punch holder, as Well as the balls such as 35, are of magnetic material such as tool steel.

In operation, when the percussion tools such as illustrated in FIGURES 4 to 10 are inserted with their shanks 20 to 25 and 32 into the bore 19 of sleeve 18, the permanent magnet 17 immediately releasably secures them in place. In the case of the ball punch of FIGURE 10, the magnetic flux of the permanent magnet 17 is sufficient to hold ball 35 in place through its magnetically conductive ball holder 3233.

The thus assembled tool holder and percussion tool inserts or bits are positioned by hand in the desired manner and place with respect to the workpiece. When a blow is struck against end 12 of the tool holder, the full compression force is transmitted directly through the tool holder 10 and a tool insert 20 to 35 inclusive, as the latter case may be, to the workpiece. The reaction forces, however, react not only on the workpiece, tool insert and tool holder, but also on the permanent magnet 17 which, being of lighter mass, rebounds in an opposite direction within the free space against the cushion 16 thus avoiding demagnetization. As these action and reaction forces derived from any single blow to the tool holder head 12 are all instantaneously applied, before the operators mental and physical sequence occurs to remove the tool to another position, the permanent magnet has gravitated back into its coupling position as shown in FIGURE 1 its magnetic properties unafiected to retain the tool within the tool holder as it is moved. The permanent magnet, however, readily releases the tools upon gentle urging by the operator when it is desired to change tool inserts, FIGURES 4 through 9, or size of ball punch 35.

Having described the invention in detail, it will be apparent to those skilled in the art that numerous modifications will be suggested, all of which as fall within the spirit of the invention being intended to fall within its scope, as best defined in the appended claims.

I claim:

1. The combination with a percussion type tool of a tool holder adapted to receive the said tool and to position the said tool with respect thereto for application to a workpiece, and a permanent magnet slidably mounted and free to move a discreet distance within said tool holder for releasably coupling said tool to the tool holder only magnetically except at the instant the tool holder has been struck a sharp blow, at which instant the permanent magnet is free to rebound whereby it is isolated from shock forces resulting from said blow.

2. The combination with a percussion type tool of a tool holder adapted to receive the said tool and to position the said tool with respect thereto for application to a workpiece, and a permanent magnet slidably mounted and free to move a discreet distance within at least a portion of said tool holder which is non-magnetic for releasably coupling said tool to the tool holder only magnetically except at the instant the tool holder has been struck a sharp blow, at which instant the permanent magnet is free to rebound whereby it is isolated from shock forces resulting from said blow.

3. The combination with a percussion type tool of a tool holder adapted to receive the said tool and to position the said tool with respect thereto for application to a workpiece, a permanent magnet slidably mounted and freeto move a discreet distance within at least a portion of said tool holder which is non-magnetic for releasably coupling said tool to the tool holder only magnetically except at the instant the tool holder has been struck a sharp blow, and a cushion against which said permanent magnet may abut after it has moved said discreet distance within the tool holder at the instant the tool holder has been struck the sharp blow, at which instant the permanent magnet is free to rebound whereby it is isolated from shock forces resulting from said blow.

4. The combination with a percussion type tool of a tool holder adapted to receive the said tool and to position the said tool with respect thereto for application to a workpiece, a permanent magnet slidably mounted and free to move a discreet distance within at least a portion of said tool holder which is non-magnetic for releasably coupling said tool to the tool holder only magnetically except at the instant the tool holder has been struck a sharp blow, and a cushion against which said permanent magnet may abut after it has moved said discreet distance within the tool holder at the instant the tool holder has been struck the sharp blow, and means for maintaining the said magnet and cushion captive with-in said tool holder, at which instant the permanent magnet is free to rebound whereby it is isolated from shock forces resulting from said blow.

5. The combination with a percussion type ball punch tool of a tool holder adapted to couple said ball punch thereto and to position said tool with respect thereto for application to a workpiece, an adapter received by the said tool holder, said adapter being provided with a concave surface in turn adapted to receive solid balls of a magnetic metal of varying diameter one at a time, means including a permanent magnet slidably mounted and free to move a discreet distance within said tool holder for releasably coupling said adapter and solid ball of a magnetic metal to the tool holder except at the instant the tool holder has been struck a sharp blow, a cushion against which said permanent magnet abuts after it has moved said discreet distance within the tool holder at the instant the tool holder has been struck the sharp blow, and means for maintaining the said magnet and cushion captive within the tool holder.

6. The combination with a percussion type tool of a tool holder adapted to receive the said tool and to position the said tool with respect thereto for application to a workpiece, said tool holder comprising a cylindrical handpiece having a fiat end for being struck, the other end of said handpiece being provided with a center bore extending a substantial distance within the said cylindrical hand piece and a counter bore of shorter length adjacent said other end, a cushion within said center bore adjacent its internal end, a tubular sleeve inserted within said counter bore, its internal opening being of lesser diameter than that of said center bore, means including a permanent magnet slidably mounted within the said center bore and free to move a discreet distance within said center bore between the said cushion and the said tubular sleeve, the portion at least of the said handpiece containing said center and counter bores being of nonmagnetic material such as stainless steel, each tool for said tool holder being of a magnetic metal composition and provided with a shoulder between its ends, and a shank extending from the shoulder adapted to slidably register with and extend its full length into said tubular sleeve, the said magnet within the handpiece abutting the said tubular sleeve and shank of the tool within it for magnetically coupling said tool to the tool holder except at the instant the tool holder has been struck a sharp blow during which instant the counter forces to said blow move the magnet away from the tool shank and against said cushion after which the magnet is again free to couple with the said shank.

References. Cited UNITED STATES PATENTS 2,671,483 3/1954 Clark 7--1 2,678,578 5/1954 Bonanno 81125 3,007,504 11/1961 Clark 81---125 3,119,423 1/1964 Weick 227147 FOREIGN PATENTS 826,580 1/1952 Germany.

CHARLES W. LANHAM, Primary Examiner.

G. P. CROSBY, Assistant Examiner. 

1. THE COMBINATION WITH A PERCUSSION TYPE TOOL OF A TOOL HOLDER ADAPTED TO RECEIVE THE SAID TOOL AND TO POSITION THE SAID TOOL WITH RESPECT THERETO FOR APPLICATION TO A WORKPIECE, AND PERMANENT MAGNET SLIDABLY MOUNTED AND FREE TO MOVE A DISCRETE DISTANCE WITHIN SAID TOOL HOLDER FOR RELEASABLY COUPLING SAID TOOL TO THE TOOL HOLDER ONLY MAGNETICALLY EXCEPT AT THE INSTANT THE TOOL HOLDER HAS BEEN STRUCK A SHARP BLOW, AT WHICH INSTANT THE PERMANENT MAGNET IS FREE TO REBOUND WHEREBY IT IS ISOLATED FROM SHOCK FORCES RESULTING FROM SAID BLOW. 